the lie: Workflow Error: System.InvalidOperationException and the Correlation Token

Whenever I get an error in the pile of logs that is SharePoint Workflow, I have to wonder how this made it through QA. Case and point: a message that returned when executing a CompleteTask activity within a workflow:

System.InvalidOperationException: Correlation value specified does not match the already initialized correlation value on declaration for activity .

This should equate to - check the correlation token you set, logically. It even seems like this is a logical conclusion from the top of procedure stack;

at ..CorrelationService.ValidateCorrelation()
at ..CorrelationService.InvalidateCorrelationToken()
..

But no, what it actually means is check the Taskid properties.

Figured out with the blog entry by Andy Burns.